Referring to FIG. 1, a forceps 10 is a known mechanical surgical instrument or device that is used to grasp or hold tissue, such as a blood vessel (BV) (generally “blood vessel”). A typical forceps 10 includes first and second shafts or elongated members 20a and 20b (generally 20) that are connected at and rotatably moveable about a connection point or pivot 24. First and second handles 30a and 30b (generally 30) at proximal ends 34a and 34b (generally 34) of the forceps 10 can be manipulated by a surgeon to move the first and second members 20a and 20b, thereby opening and closing jaw or clamping members 40a and 40b (generally 40) at the distal ends 44a and 44b (generally 44) of the forceps 10 to release and grasp the blood vessel. A forceps 10 may include interlocking ratchets 50a and 50b (generally 50) to lock the position of the members 20a and 20b and jaws 40a and 40b. Inner faces or surfaces 41a and 41b (generally 41) of respective jaws 40a and 40b contact a blood vessel can be straight or have a needle-nose like shape (as shown in FIG. 2) and can also have a curved shape (as shown in FIG. 3). A contact surface 41 of a jaw 40 may have a grooved or ridged surface 60 in order to more securely grasp the blood vessel there between.
Referring to FIG. 4, it is known to apply electrical current (C) to a forceps 10 in order to coagulate, cauterize or seal a blood vessel that is held between the jaws 40. Cauterization involves burning or necrosing the vessel by rupturing and drying the vessel tissue. Sealing a blood vessel involves liquefying collagen in the vessel tissue so that it reforms or fuses into a mass, which prevents blood from passing through the vessel.
One known method of applying electrical current to a blood vessel using a forceps 10 is to contact or tap a forceps handle 30 or shaft member 20 with a wire, lead or electrode 72. The electrode 72 is coupled to a source of electrical current 70, such as a radio frequency or RF generator or other suitable power source (generally RF generator). Electrical current conducts from the RF generator, through the forceps 10, and to the blood vessel whenever the RF generator 70 is active and a surgeon brings the electrode 72 in contact with the forceps 10.
While known “tap” devices and techniques have been used in the past with some effectiveness, they can be improved. For example, as shown in FIG. 4, when the electrode 72 is brought into contact with the forceps 10, electrical current conducts through all of the conductive forceps 10 components within a conductive path. Thus, electrical current may conduct through the handles 30, the shaft members 20, the jaws 40 and then to the blood vessel to be treated. As a result, current is applied “globally,” i.e., to the blood vessel and also to tissue surrounding the forceps 10. Thus, such devices and techniques do not apply current “locally” to a selected region at a distal end 44 of a jaw 40 that holds the blood vessel to be treated.
Thus, with known “contact” or “tap” devices and techniques, larger currents must be applied to the forceps 10 to compensate for current that is conducted to surrounding tissue in order to achieve desired cauterization or sealing results at the target vessel held by the jaws members 40. Additionally, vessel engaging surfaces 48 are permanent or integrally formed components and, therefore, cannot be removed or replaced after a procedure. Consequently, jaw members 40 must be sterilized after each use, which is costly, time consuming and inconvenient. Further, jaw members 40 may be damaged during use. Damaged jaw members 40 may result in inconsistent cauterization and sealing when the same forceps 10 are used during subsequent procedures.
Another known device for applying electrical current to a blood vessel is described in U.S. Pat. No. 6,050,996 to Schmaltz, et al. (Schmaltz). Schmaltz describes a specialized forceps device that includes modified jaws having a mechanical interface or socket. The forceps device also includes electrodes that are designed with a particular interface or socket configuration that mates with or snaps into the mechanical interface or socket of the jaws. Wires extending from the electrodes are used to deliver current to the tissue.
The interface/socket design described by Schmaltz may allow electrodes to be replaced after each use, but such devices have a number of limitations and disadvantages. Significantly, users are required to purchase a special forceps that includes the sockets and, in addition, required to purchase special electrodes that include sockets capable of mating with the sockets. Thus, the types of forceps and electrodes that can be used are limited. Further, the device describe by Schmaltz is not suitable for converting known and widely used mechanical forceps devices into electro-surgical devices. Rather, such specialized devices serve as more expensive replacement devices with which only certain replacement electrode components can be used.
Another known device for configuring a forceps as a coagulation device is described in U.S. Publication No. 2003/0158549 A1 to Swanson (“Swanson”), the contents of which are incorporated herein by reference. Devices described by Swanson include clamp and base members including an energy transmission device that applied to a clamp member by interfacing mating structures. Swanson describes base members having an aperture for receiving an end of a clamp member inside the base member, and certain described devices include other apertures and holes inside the base member through which wires are placed, and a temperature sensor within the base member. These types of structural configurations and additional components may complicate the design and manufacture of devices.
Accordingly, it would be desirable to have an electro-surgical device, such as an electro-surgical forceps, that can apply electrical current to a localized, targeted area. Further, it would be advantageous to have this ability while using less power. It would also be desirable to have the ability to adapt or convert standard, widely used mechanical forceps or other devices for use in electro-surgery. It would also be desirable to provide electro-surgical attachments that can adapt or convert standard mechanical forceps into electro-surgical devices that are easy to apply, easy to remove, cost effective, replaceable and disposable. These improvements would allow forceps attachments to be discarded after use and new attachments to be applied for subsequent procedures. These improvements would also prevent previously used attachments that may have damaged electrodes from being repeatedly used, thereby improving vessel cauterization and sealing results. This also ensures that new, sterile attachments are used, thereby eliminating the need to re-sterilize components that were used during a previous procedure. It would also be beneficial to have forceps with electro-surgical capabilities without having to purchase specialized forceps devices and specialized electrodes having mating mechanical interfaces.